Gate valve with seat assembly

ABSTRACT

The present invention provides a gate valve assembly having a valve body with a channel extending from a distal end to a proximal end, a gate configured to be moved from a first position to a second position, the second position being when the gate is positioned in the channel of the valve body between the distal end and the proximal end of the valve body. A seat insert is also provided to be threaded into a pocked of the valve body and a seat is configured to be positioned within the seat insert. A seal is adapted within a groove of the seat insert positioned between the valve body and the seat insert, wherein the seal is a fixed static seal providing no gaps and/or spaces between the seal insert and the valve body allowing no debris to corrupt the seals.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/311,419, filed Jun. 23, 2014 and entitled “Gate Valve with SeatAssembly”, which claims priority to U.S. Provisional Patent ApplicationSer. No. 61/843,701 filed on Jul. 8, 2013. The content of each of theabove applications is hereby incorporated by reference.

FIELD OF THE INVENTION

The present disclosure generally relates to gate valves and inparticular to an improved seat assembly.

BACKGROUND

Gate valves that are used in the oil and gas industry typically have abody with a flow passage extending through it. The flow passageintersects a central cavity. A gate is provided to move through thecentral cavity to block the flow passage. Seal rings are used to bridgea gap between the valve body and the gate to prevent fluid from flowingaround the gate when the gate blocks the flow passage. There is a needfor an improved seat assembly to prevent leaks in the valve.

SUMMARY

A gate valve assembly is provided in one exemplary embodiment. Theassembly provides a valve body having an opening, a seat insertconfigured to be threaded it to the opening of the valve body, and aseat configured to be positioned within the seat insert.

The features and advantages of the present invention will be readilyapparent to those skilled in the art. While numerous changes may be madeby those skilled in the art, such changes are within the spirit of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

To further clarify the features of the present invention, a moreparticular description of the invention will be rendered by reference tospecific embodiments thereof, which is illustrated in the appendeddrawings. It is appreciated that these drawings depict only typicalembodiments of the invention and are therefore not to be consideredlimiting of its scope. The invention will be described and explainedwith additional specificity and detail with the accompanying drawings inwhich:

FIG. 1 illustrates a gate valve assembly in accordance with oneembodiment of the present invention;

FIG. 2 illustrates a seat assembly in accordance with the embodimentillustrated in FIG. 1 of the present invention;

FIG. 3 illustrates a seat assembly positioned on one side of a gatevalve assembly in accordance with one embodiment of the presentinvention;

FIG. 4 illustrates an exploded view of a seat assembly according to thepreset invention; and

FIG. 5 illustrates another view of the gate valve assembly according thepresent invention.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

The following discussion is directed to various embodiments of theinvention. Although one or more of these embodiments may be preferred,the embodiments disclosed should not be interpreted, or otherwise used,as limiting the scope of the disclosure, including the claims. Inaddition, one skilled in the art will understand that the followingdescription has broad application, and the discussion of any embodimentis meant only to be exemplary of that embodiment, and not intended tointimate that the scope of the disclosure, including the claims, islimited to that embodiment.

FIG. 1 illustrates an improved gate valve assembly. The gate valveassembly is provided with a hand wheel 1, a packing stem 6, a bonnet 14,operating stem 19, a gate 20, a valve body 25, and agate valve seatingassembly 100. In operation, the gate valve assembly 100 is configured sothat as the hand wheel 1 is actuated, the operating stem 19 is moved sothat the gate 20 can either close or open the channel in the valve body25. When the gate 20 is in an open position, fluid is allowed to flowthrough the channel in the valve body 25. When the gate is in a closedposition, the flow of fluid is disrupted within the channel. A gatevalve seating assembly 100 is provided between the valve body 25 and thegate 20 so that leakage of fluid from the channel when the gate isclosed may be prevented. In the preferred embodiment, a two-way gatevalve assembly is provided such that either the upstream line and thedownstream line can be attached to either side of the valve body.

Bonnet 14 is mounted to the valve body 25 by studs 16 and secured withhex nuts 27. The bonnet 14 is sealed with respect to the valve body 25by bonnet gaskets 17. Packing stem 6 provides a seal between the bonnet14 and the operating stem 19. The seal assemblies between the valve body25 and the gate valve are described in greater detail with reference toFIGS. 2-5. Attached to the bonnet 14 are also autoclave fittings 12 and15. Autoclave fitting 15 is a bleed port or a pressure release valvewhich allows an operator to release pressure with respect to the valvebody and the gasket. Autoclave fitting 12 is a grease port fitting whichallows an operator to introduce a lubricant between the bonnet 14 andthe gate 20.

Now turning to FIGS. 2 and 3, an exploded view of an improved gate valveseat assembly 100 in a preferred embodiment of the present invention isprovided. Seating assemblies are positioned as to surround channel 101and are preferably circular in construction and preferably mount intocylindrical shaped pockets. The gate valve assembly 100 is illustratedin greater detail. The gate valve assembly 100 comprises a gate 102which is used to control the flow through the flow bore channel 101 whenthe gate 102 is actuated. The assembly 100 also includes first andsecond seat inserts 104, 106 on opposing sides of the gate 102. Thefirst and second seat inserts 104 and 106 are threaded into the valvebody 108. It should be noted that the first and second seat inserts 104and 106 may be coupled to the valve body 108 by any mechanical methodssuch as press fittings or any other mechanical means. In the preferredembodiment the seat inserts 104 and 106 are threaded into the valvebody. The threads are configured so that the seat inserts may notunthread without an operator.

Annular seals 111 and 112 are positioned between the seat inserts 104and 106 and the valve body 110. These seals 111, 112 may be O-ringsand/or spring energized type seals. Any other type of mechanicallyviable seal may also be used. The seals 111, 112 may be composed ofpolymer, elastomeric, non-elastomeric, and/or metallic material or somecombination thereof and are configured to be suitable to any applicationdepending on the variability of environmental factors such as flowpressure (low/high) and temperature.

The seals 111, 112 are further adapted to be positioned within a grooveof the seat inserts 104 and 106. The seat inserts 104 and 106 arefurther configured to receive and accommodate seats 114 and 116 in acounter bore channel with seals 117 and 118 on the outside diameter ofthe seats 114 and 116. Springs 120 and 122 are also provided which arepositioned between each of the seat inserts 104 and 106 and the backface of each one of the seats 114 and 116.

Springs 120 and 122 may include several components, spacers, bushings,rings, and the like as desired to provide an initial seal force. Springs120 and 122 are preferably circular and surrounds channel 101. In thepreferred embodiment, a metallic ring seal 113 is used to provideadditional protection against any debris that may enter the spacebetween the seat insert and valve body. This allows protection of thespace between the valve body and the seat insert as well as providingprotection for the seals 111 and 112.

The arrangement of the seals and the seat inserts 104, 106 enable astatic seal between the valve body pocket and the fixed seat inserts 104and 106. The static seals 111-113 provide the benefit of allowing nogaps and/or spaces between the seat inserts 104 and 106 and the valvebody 108, thereby allowing no debris or solids to corrupt the seals111-113 which are positioned in a groove within the seat inserts 104 and106. The fixed seat inserts 104 and 106 and the seats 114 and 116 areconfigured so that they are in continuous contact with the surface ofthe gate 102 through the spring force provided by the springs 120 and122. Since the seats 114 and 116 are in continuous contact with the gatesurface, a very limited dynamic action of the seat seals 117 and 118 areprovided.

The above arrangement of the components of the valve assembly 100provides that the pressure from the flow bore channel 101 effectivelyseals all the passages by seals 111-113 and seals 117 and 118. They alsoallow for continuous contact between the seats 114 and 116 and the gate102 by the use of spring 120, thereby allowing for sealing at maximumdesigned working pressures including of the valve and in low pressuresas required. The seat inserts 104 and 106 being fixed into the valvebody 110 (pressure containing element) provides the additional benefitof protection from erosion and corrosion caused by debris and otherunwanted solids which cannot enter into the space between the seatinserts 104 and 106 and the valve body 108. As a result of using fixedseat inserts, the seals become static as provided in the preferredembodiment, the valve body assembly benefits with a longer life spancompared to using dynamic seals and non-fixed seat inserts.

The surfaces of the seats 114 and 116 are adapted to be able to sealgate 102. The surfaces may be provided with various indentations or afinished surface having a surface area that may be larger or smallerthan other surface areas of the seating assembly to effect a variableforce acting against the gate so that the sealing force that pushes thesurfaces is greater than the force that would urge the two surfacesapart.

FIG. 4 illustrates an exploded view of the seat assembly 200. The seatassembly 200 includes a seat retainer 202, a disc spring 204 positionedwithin a groove of the seat retainer 202, a trash ring 206 positionedwithin the seat retainer 202. A seat assembly 200 also includes a seatthat is configured to with within the groove of the seat retainer 202.That assembly 200 further includes high pressure/high temperature seals210 positioned between the seat retainer 202 and the valve body. Theseat 20 is also provided with at least one high pressure/hightemperature seal 212.

FIG. 5 illustrates the seat assemblies 200 and 220 positioned within avalve body when the gate is in a closed position. As illustrated in FIG.5, seat assemblies 200 and 220 are positioned on the both the upstreamand downstream portions of the valve body. As a result, the seatingmechanism used in the seat assemblies provides improved sealing on boththe upstream and downstream of the valve body. The seat retainers 202and 222 are threaded into the valve body 201. High pressure/Hightemperature seals 210 and 224 are positioned between the seat retainers202 and 222 and the valve body 201. Although high pressure/hightemperature seals are used in this embodiment, any type of seal may beused.

During operation of the gate valve, the fluid enters into the channeland the valve body pressure is automatically de-energized to thedownstream pressure and this is achieved by the valve body pressurewhich moves the seat toward the seat insert by pushing the springcreating a gap between the gate and the seat. As a result, the valvebody pressure is drained to equal to the lowest pressure of the sides.

Thus, an embodiment includes a gate valve assembly, some of which isshown in the embodiment of FIG. 3. The assembly includes a valve bodyhaving a channel extending from a distal channel portion at a distal endof the valve body to a proximal channel portion at a proximal end of thevalve body. The assembly includes a gate 101 configured to move betweenopen and closed positions, the closed position being when the gate is inthe channel. The assembly includes a first seat insert 104 and a secondseat insert in first and second pockets of the valve body and onopposing sides of the gate from one another. A first seat 114 is betweenthe first seat insert and the gate and a second seat is between thesecond seat insert and the gate. The assembly includes a static firstseal (e.g., seal 111) between the valve body and the first seat insertand a static second seal between the valve body and the second seatinsert. The assembly includes a first spring 122 directly contacting thefirst seat and the first seat insert and a second spring directlycontacting the second seat and the second seat insert. In the assembly(a)(i) the first seat has a first proximal outer diameter (e.g.,directly adjacent spring 122 and measured vertically in parallel to longaxis of gate 101) and a first lip (e.g., directly adjacent gate 101)having a first distal outer diameter, (a)(ii) the first distal outerdiameter is between the gate and the first proximal outer diameter, and(a)(iii) the first distal outer diameter is greater than the firstproximal diameter. In the assembly (b)(i) the second seat has a seconddistal outer diameter and a second lip having a second proximal outerdiameter. (b)(ii) the second proximal outer diameter is between the gateand the second distal outer diameter, and (b)(iii) the second proximalouter diameter is greater than the second distal diameter. In theassembly inner surfaces of each of the first and second seat inserts andeach of the first and second seats each at least partially form thechannel and are each configured to directly contact fluid when the fluidis traversing the channel. In the assembly the first spring isconfigured such that: (c)(i) the first spring biases the first seatagainst the gate when there is no fluid pressure in the proximal channelportion, (c)(ii) the first spring directly contacts the fluid when thereis fluid pressure in the proximal channel portion. (c)(iii) the fluidforces the first seat against the gate when there is fluid pressure inthe proximal channel portion. (c)(iv) the first spring biases the firstseat insert towards the static first seal (e.g., seal 111) and againstthe valve body when there is no fluid pressure in the proximal channelportion, and (c)(v) the first spring compresses, when fluid pressure inthe valve body exceeds fluid pressure in the proximal channel portion,to allow the first seat to move towards the first seat insert to lowerthe fluid pressure in the valve body. In the assembly the second springis configured such that: (c)(i) the second spring biases the second seatagainst the gate when there is no fluid pressure in the distal channelportion, (c)(ii) the second spring directly contacts the fluid whenthere is fluid pressure in the distal channel portion, (c)(iii) thefluid forces the second seat against the gate when there is fluidpressure in the distal channel portion, (c)(iv) the second spring biasesthe second seat insert against the valve body when there is no fluidpressure in the distal channel portion, and (c)(v) the second springcompresses, when fluid pressure in the valve body exceeds fluid pressurein the distal channel portion, to allow the second seat to move towardsthe second seat insert to lower the fluid pressure in the valve body.

In the embodiment of FIG. 3 the assembly includes a first dynamic seal(e.g., seal 118) in a first slot between the first seat and the firstseat insert and a second dynamic seal in a second slot between thesecond seat and the second seat insert.

In the embodiment of FIG. 3 the first and second springs are configuredsuch that: the first spring biases the first seat against the gate whenthere is fluid pressure in the proximal channel portion; the firstspring biases the first seat insert against the valve body when there isfluid pressure in the proximal channel portion; the second spring biasesthe second seat against the gate when there is fluid pressure in thedistal channel portion; and the second spring biases the second seatinsert against the valve body when there is fluid pressure in the distalchannel portion.

In the embodiment of FIG. 3 the first seat includes a first sidewall(e.g., directly adjacent spring 122 and extending vertically) thatcouples to the inner surface (extending horizontally) of the first seatand the second seat includes a second sidewall that couples to the innersurface of the second seat. The fluid forces the first seat against thegate, when there is fluid pressure in the proximal channel portion, bydirectly contacting the first sidewall; and the fluid threes the secondseat against the gate, when there is fluid pressure in the distalchannel portion, by directly contacting the second sidewall.

While it is apparent that the invention disclosed herein is wellcalculated to fulfill the objects stated above, it will be appreciatedthat numerous modifications and embodiments may be devised by thoseskilled in the art.

What is claimed is:
 1. A gate valve assembly comprising: a valve bodyhaving a channel extending from a distal end of the valve body to aproximal end of the valve body; a gate configured to be moved from afirst position to a second position, the second position being when thegate is positioned in the channel between the distal end and theproximal end; at least one seat insert configured to be threaded into apocket of the valve body; a seat configured to be positioned within theseat insert; a trash ring, including a plurality of holes, positionedwithin a first groove of the seat insert and the seat; and a seal withina second groove of the seat insert and positioned between the valve bodyand the seat insert, wherein the seal is a fixed static seal; wherein aspring, positioned between the seat and the seat insert, is configuredto (a) flex and seal the seat against the gate when valve body pressurein the valve body is lower than a channel pressure in the channel, and(b) compress, when the valve body pressure exceeds the channel pressure,to lower the valve body pressure.
 2. A gate valve assembly comprising: avalve body having a channel extending from a distal channel portion at adistal end of the valve body to a proximal channel portion at a proximalend of the valve body; a gate configured to move between open and closedpositions, the closed position being when the gate is in the channel;first and second seat inserts screwed into first and second pockets ofthe valve body and on opposing sides of the gate from one another; ametal first seat that directly contacts the first seat insert and thegate and a metal second seat that directly contacts the second seatinsert and the gate; a static first seal that directly contacts thevalve body and the first seat insert and a static second seal thatdirectly contacts the valve body and the second seat insert; anadditional static first seal that directly contacts the valve body andthe first seat insert, and an additional static second seal thatdirectly contacts the valve body and the second seat insert; a firstspring directly contacting the first seat and the first seat insert anda second spring directly contacting the second seat and the second seatinsert; a first dynamic seal at least partially included in a first slotand directly contacting the first seat and the first seat insert, thefirst slot existing between the first seat and the first seat insert; asecond dynamic seal at least partially included in a second slot anddirectly contacting the second seat and the second seat insert, thesecond slot existing between the second seat and the second seat insert;wherein (a)(i) the first seat has a first proximal outer diameter and afirst lip having a first distal outer diameter, (a)(ii) the first distalouter diameter is between the gate and the first proximal outerdiameter, and (a)(iii) the first distal outer diameter is greater thanthe first proximal diameter; wherein (b)(i) the second seat has a seconddistal outer diameter and a second lip having a second proximal outerdiameter, (b)(ii) the second proximal outer diameter is between the gateand the second distal outer diameter, and (b)(iii) the second proximalouter diameter is greater than the second distal diameter; wherein innersurfaces of each of the first and second seat inserts and each of thefirst and second seats each at least partially form the channel and areeach configured to directly contact fluid when the fluid is traversingthe channel; wherein the first spring is configured such that: (c)(i)the first spring biases the first seat against the gate when there is nofluid pressure in the proximal channel portion, (c)(ii) the first springdirectly contacts the fluid when there is fluid pressure in the proximalchannel portion, (c)(iii) the fluid forces the first seat against thegate when there is fluid pressure in the proximal channel portion,(c)(iv) the first spring biases the first seat insert towards the staticfirst seal and the additional static first seal and against the valvebody when there is no fluid pressure in the proximal channel portion,and (c)(v) the first spring compresses, when fluid pressure in the valvebody exceeds fluid pressure in the proximal channel portion, to allowthe first seat to move towards the first seat insert to lower the fluidpressure in the valve body; wherein the second spring is configured suchthat: (c)(i) the second spring biases the second seat against the gatewhen there is no fluid pressure in the distal channel portion, (c)(ii)the second spring directly contacts the fluid when there is fluidpressure in the distal channel portion, (c)(iii) the fluid forces thesecond seat against the gate when there is fluid pressure in the distalchannel portion, (c)(iv) the second spring biases the second seat insertagainst the valve body when there is no fluid pressure in the distalchannel portion, and (c)(v) the second spring compresses, when fluidpressure in the valve body exceeds fluid pressure in the distal channelportion, to allow the second seat to move towards the second seat insertto lower the fluid pressure in the valve body; wherein the first seat isconfigured to prevent the first seat insert from directly contacting thegate; wherein the first seat and the gate are configured to form ametal-to-metal seal; wherein the metal-to-metal seal has an uppermostpoint of contact between the gate and the first seat and a lowermostpoint of contact between the gate and the first seat; wherein themetal-to-metal seal is configured so, between the uppermost point ofcontact and the lowermost point of contact, only metal materials of thegate and the first seat directly contact each other.
 3. The assembly ofclaim 2, wherein: the first and second springs are configured such that:the first spring biases the first seat against the gate when there isfluid pressure in the proximal channel portion; the first spring biasesthe first seat insert against the valve body when there is fluidpressure in the proximal channel portion; the second spring biases thesecond seat against the gate when there is fluid pressure in the distalchannel portion; the second spring biases the second seat insert againstthe valve body when there is fluid pressure in the distal channelportion; and the first dynamic seal is a high pressure seal.
 4. Theassembly of claim 2, wherein: the first seat includes a first sidewallthat extends from the inner surface of the first seat; the second seatincludes a second sidewall that extends from the inner surface of thesecond seat; the fluid forces an additional first sidewall of the firstseat directly against the gate to form the metal-to-metal seal, whenthere is fluid pressure in the proximal channel portion, in response tothe fluid directly contacting the first sidewall; the fluid forces thesecond seat against the gate, when there is fluid pressure in the distalchannel portion, by directly contacting the second sidewall; and thefirst seat includes a monolithic metal portion that extends from thefirst sidewall to the additional first sidewall.
 5. The assembly ofclaim 2, wherein: an axis intersects the static first seal, the firstseat insert, the first seat, and the gate when the gate is closed; theaxis is parallel to a long axis of the channel; an additional axis,which is not parallel to the long axis, intersects both the static firstseal and the additional static first seal.
 6. The assembly of claim 5comprising: another static first seal between the valve body and thefirst seat insert; wherein the additional axis does not intersect theanother static first seal.
 7. The assembly of claim 2 comprising anotherstatic first seal between the valve body and the first seat insert. 8.The assembly of claim 7 wherein: the static first seal and theadditional static first seal are both spring energized seals; the staticfirst seal and the additional static first seal both include metal; andthe another static first seal includes metal.
 9. The assembly of claim8, wherein: the first slot includes a channel having a bottom andsidewalls that couple connect to each other via the bottom; the bottomand the sidewalls are all exterior wall portions of the first seat; atleast a portion of the first dynamic seal simultaneously and directlycontacts the bottom and the sidewalls.
 10. The assembly of claim 9,wherein: the another static first seal is between the static first sealand a plurality of threads; the first seat insert is screwed into thefirst pocket of the valve body via the threads; the first springsurrounds the channel; the static first seal is included in a channellocated in a face of the first seat insert; the additional static firstseal is included in an additional channel located in the face of thefirst seat insert; the first dynamic seal is located between the firstspring and the gate.